1 Field of the Invention
The invention is based on a rotary piston pump for gaseous media.
2 Description of the Prior Art
In a known rotary piston pump of this type (German Patent DE 42 41 320 C2), it is an essential characteristic that “the teeth of the part cooperating in meshing fashion with the cycloidal part have corresponding tooth combs, which extend along the flanks of the cycloidal part, and the tooth combs have a freely designable radius”. As a result, on its use as a pump, a high degree of tightness between the tooth combs of the blocking part and the flanks of the cycloidal part is attained, which is of considerable importance especially when used as a low-pressure pump or vacuum pump. In such a pump having a cycloidal part, providing the power part and the blocking part both in double fashion is already done in this known pump, in which it is also possible for the two work chambers to communicate with one another, even though they are the same size.
It is known that by connecting the work chambers in this way, a corresponding increase in the capacity of each, that is, the pumping capacity, occurs compared to if the work chambers of only one power part were used. It is true that by such a parallel connection, the delivery capacity would be correspondingly increased. However, the pressure would remain the same, assuming it is not controlled in some extra way. Last but not least, the entrainment of the second power part in this known pump, via a common ring acting as a work part, is not unproblematic, quite aside from the fact that producing such a pump, especially if it is to be driven via an electric motor, is complicated.